I have been using Sonar X3 pretty successfully for the last few months.
I have always recorded one track at a time.
I am using a Roland Quadcapture interface.
Today I had two friends over and we had two mics set up and recorded two audio tracks simultaneously while playing a synth drum beat on a third track.   About every three minutes the drum track and all recording would stop and I'd have an error box in the lower right corner that said "Audio device stopped unexpectedly."   After about 30 seconds, we'd be able to start up again and then three minutes later it would happen again.
Any ideas why this would happen and how to correct it.

Hi Mr Bonez
 
Could you confirm what your OS is, and whether it is 32 bit or not, also are you running X3D?
 
Also please could you make sure you are on system update 1.04 and on 1.5.2 drivers.
http://www.roland.co.uk/products/productdetails.aspx?p=1166
 
Also please check windows update is fully up to date (as I notice your interface is USB).
Finally please perform a defrag.
 
That will give us a base platform to troubleshoot on (assuming the issue persists after this). Thanks..

I am using WIndows 7 home.   I just check my drivers and I'm still on v. 1.0.1Thanx for making me aware of that.

Freeze the synth-drum - that'll help tremendously as well.

It happened with just the 2 audio tracks too.
FUnny thing when I install the updated drivers and I try to go to the control panel for the quad capture under the devices, it doesn't come up.  It says unavailable.
Any ideas about this?

Did you uninstall the previous drivers first (I think I saw that in the instructions on the web page) and reboot?
And the other stuff I said in #2 (esp system update, windows update).
 
Thanks.